选用ISDN业务进行（）是明智的选择。①网上冲浪；②短电文发送与

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问题单项选择题

选用ISDN业务进行（）是明智的选择。①网上冲浪；②短电文发送与接收；③视频数据传输；④电视会议；⑤商务电子；⑥保密电话

A.①②⑤

B.①②

C.①②③⑤

D.③④⑥

答案

参考答案：D

补全对话，情景问答

根据语境，用恰当的语言完成对话。

(After the graduation ceremony, Kang Kang and Li Ming are talking about their summer vacation plans at home.)

Kang Kang = K Li Ming = L

K: Hey, Li Ming. Summer vacation is coming. What are you going to do this special summer vacation?

L: 1.___________. My sister works in a clothes factory there, I hear it is a modern, beautiful developed city.

K: Sounds great. 2.____________?

L: Since last year. She has been working there after her graduation.

K: 3.___________?

L: By train. You know Wuguang Express works well, people from Wuhan can take Wuguang Express there.

K: 4____________?

L: About three hours. More and more people prefer to go there by express.

K: That's right. 5______________?

L: In half a month. My parents will go and see my sister with me.

K: Have a good trip.

L: Many thanks.

问答题

如图所示零件，经过工序1、工序2加工达到零件图尺寸要求。试建立工艺尺寸链，标明各环性质，求工序尺寸A₁、A₂的基本尺寸及偏差。